TY - JOUR
T1 - Temperature-induced pseudopolymorphism of molecular salts from a pyridyl bis-urea macrocycle and naphthalene-1,5-disulfonic acid
AU - Som, Bozumeh
AU - Shue, Jessica R.
AU - Smith, Mark D.
AU - Shimizu, Linda S.
N1 - Publisher Copyright:
© 2018 International Union of Crystallography.
PY - 2018/1
Y1 - 2018/1
N2 - Molecular salts, often observed as cocrystals, play an important role in the fields of pharmaceutics and materials science, where salt formation is used to tune the properties of active pharmaceutical ingredients (APIs) and improve the stability of solid-state materials. Salt formation via a proton-transfer reaction typically alters hydrogen-bonding motifs and influences supramolecular assembly patterns. We report here the molecular salts formed by the pyridyl bis-urea macrocycle 3,5,13,15,21,22-hexaazatricyclo[15.3.1.17,11]docosa-1(21),7(22),8,10,17,19-hexaene-4,14-dione, (1), and naphthalene-1,5-disulfonic acid (H2NDS) as two salt cocrystal solvates, namely 4,14-dioxo-3,5,13,15,21,22-hexaazatricyclo[15.3.1.17,11]docosa-1(21),7(22),8,10,17,19-hexaene-21,22-diium naphthalene-1,5-disulfonate dimethyl sulfoxide disolvate, C16H20N6O22+·C10H6O6S22-·2C2H6OS, (2), and the corresponding monosolvate, C16H20N6O22+·C10H6O6S22-·C2H6OS, (3). This follows the ΔpKa rule such that there is a proton transfer from H2NDS to (1), forming the reported molecular salts through hydrogen bonding. Prior to salt formation, (1) is relatively planar and assembles into columnar structures. The salt cocrystal solvates were obtained upon slow cooling of dimethyl sulfoxide-acetonitrile solutions of the molecular components from two temperatures (363 and 393 K). The proton transfer to (1) significantly alters the conformation of the macrocycle, changing the formerly planar macrocycle into a step-shaped conformation with trans-cis urea groups in (2) or into a bowl-shape conformation with trans-trans urea groups in (3).
AB - Molecular salts, often observed as cocrystals, play an important role in the fields of pharmaceutics and materials science, where salt formation is used to tune the properties of active pharmaceutical ingredients (APIs) and improve the stability of solid-state materials. Salt formation via a proton-transfer reaction typically alters hydrogen-bonding motifs and influences supramolecular assembly patterns. We report here the molecular salts formed by the pyridyl bis-urea macrocycle 3,5,13,15,21,22-hexaazatricyclo[15.3.1.17,11]docosa-1(21),7(22),8,10,17,19-hexaene-4,14-dione, (1), and naphthalene-1,5-disulfonic acid (H2NDS) as two salt cocrystal solvates, namely 4,14-dioxo-3,5,13,15,21,22-hexaazatricyclo[15.3.1.17,11]docosa-1(21),7(22),8,10,17,19-hexaene-21,22-diium naphthalene-1,5-disulfonate dimethyl sulfoxide disolvate, C16H20N6O22+·C10H6O6S22-·2C2H6OS, (2), and the corresponding monosolvate, C16H20N6O22+·C10H6O6S22-·C2H6OS, (3). This follows the ΔpKa rule such that there is a proton transfer from H2NDS to (1), forming the reported molecular salts through hydrogen bonding. Prior to salt formation, (1) is relatively planar and assembles into columnar structures. The salt cocrystal solvates were obtained upon slow cooling of dimethyl sulfoxide-acetonitrile solutions of the molecular components from two temperatures (363 and 393 K). The proton transfer to (1) significantly alters the conformation of the macrocycle, changing the formerly planar macrocycle into a step-shaped conformation with trans-cis urea groups in (2) or into a bowl-shape conformation with trans-trans urea groups in (3).
KW - crystal structure
KW - macrocycle
KW - molecular salts
KW - naphthalenedisulfonic acid
KW - polymorphism
KW - pyridyl bis-ureas
UR - http://www.scopus.com/inward/record.url?scp=85040175573&partnerID=8YFLogxK
U2 - 10.1107/S2053229617017600
DO - 10.1107/S2053229617017600
M3 - Article
C2 - 29303500
AN - SCOPUS:85040175573
SN - 2053-2296
VL - 74
SP - 75
EP - 81
JO - Acta Crystallographica Section C: Structural Chemistry
JF - Acta Crystallographica Section C: Structural Chemistry
IS - 1
ER -